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Watlow EZ-ZONE PM User Manual

Page 92

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Watlow EZ-ZONE

®

PM Limit Controller

89

Appendix

Detection of and Rules Around Abnormal Sensor Conditions

Inputs

Detection of Abnormal Conditions

Thermocouple
Shorted

No direct detection, Open loop firmware detection.

Open

Yes, Parasitic pull-up

Reversed

Yes, firmware detection

Current Source
Shorted

Range limiting only

Open

Range limiting only

Reversed

Range limiting only

Voltage Source
Open

Range limiting only

Shorted

Range limiting only

Reversed

Range limiting only

RTD
S1 open Yes, pulled up.
S2 open

Not implemented.

S3 open Yes, pulled up.

S1 short to S2 Yes, pulled up
S1 short to S3 Yes, pulled down to under range.
S2 shorted to S3 Not implemented, Possible, monitor S2 voltage.
S1 and S2 open Yes, pulled down to under range.
S1 and S3 open Yes, S1 pulled up.

S2 and S3 open Yes pulled up.
Thermistor
S1 open Yes, pulled up to sensor over range.
S3 open Yes, pulled up to sensor over range.
S1 short to S3 Yes, pulled down to sensor under range.
S1 and S3 open Yes, S1 pulled up to sensor over range.